Extraction columns design

In extraction column design, the model equations are normally expressed in terms of superficial phase velocities, L and G, based on unit cross-sectional area. The volume of any stage in the column is then A H, where A is the cross-sectional area of the column. Thus the volume occupied by the total dispersed phase is h A H, where h is the fractional holdup of dispersed phase, i.e., the droplet volume in the stage, divided by the total volume of the stage and the volume occupied by the continuous phase, in the stage, is (1-h) A H. 

Table 2 Input data and results from Aspen Distill for extraction column design...

Extraction, a unit operation, is a complex and rapidly developing subject area (1,2). The chemistry of extraction and extractants has been comprehensively described (3,4). The main advantage of solvent extraction as an industrial process Hes in its versatiHty because of the enormous potential choice of solvents and extractants. The industrial appHcation of solvent extraction, including equipment design and operation, is a subject in itself (5). The fundamentals and technology of metal extraction processes have been described (6,7), as has the role of solvent extraction in relation to the overall development and feasibiHty of processes (8). The control of extraction columns has also been discussed (9). 

Kuhni contacters (Eig. 15e) have gained considerable commercial application. The principal features are the use of a shrouded impeller to promote radial discharge within the compartments, and a variable hole arrangement to allow flexibility of design for different process applications. Columns up to 5 m in diameter have been constmcted (176). Description and design criteria for Kuhni extraction columns have been reported (177,178). 

Extractive Distillation Design and Optimization Extractive distillation column composition profiles have a veiy characteristic... 

This section concerns the modelling of countercurrent flow, differential mass transfer applications, for both steady-state and non-steady-state design or simulation purposes. For simplicity, the treatment is restricted to the case of a single solute, transferring between two inert phases, as in the standard treatments of liquid-liquid extraction or gas absorption column design. 

Extraction column packed column, diameter 0.5 m, height 4 m, packed height 3 m, packing 25 mm stainless steel pall rings, design pressure 2 bar, material carbon steel. 

The design of extraction columns is discussed in Chapter 11, Section 11.16. See also, Volume 2, Chapter 13, Walas (1990) and Perry et al. (1997). 

Aspec is designed to receive up to 108 samples. The system is compatible with most standard disposable extraction columns. Analytichem Bond-Elut Baker SPE, Supelco Supelclean, Alltech Extract Clean, etc. There is a choice of more than 20 different stationary phases. 

Snyder columns are designed to allow highly volatile solvents to escape while retaining semivolatile analytes of interest. Snyder columns are generally fitted onto the tops of flasks containing extracts, and column design permits solvent to escape as the flask is heated. The analytes of interest condense from a gas to a liquid phase and fall back into the solvent reservoir. The Kudema-Danish concentrator is a Snyder column with a removable collection tube attached to the bottom. As solvent is evaporated, the extract is collected in the collection tube. 

From experiments, equations have been derived that enable calculation of the minimum velocity in the nozzle, the nozzle velocity, and the Sauter diameter at the drop size minimum. They provide the basis for the correct design of a sieve tray [3,4]. Figure 9.4a shows the geometric design of sieve trays and their arrangement in an extraction column. Let us again consider toluene-phenol-water as the liquid system. The water continuous phase flows across the tray and down to the lower tray through a downcomer. The toluene must coalesce into a continuous layer below each tray and reaches... 

A.E. Karr, Design scale up and application of the reciprocating plate extraction column, Sep. Sci. Technol. 15, 877-905 (1980). 

Bart HJ. Reactive extraction of acids and metals—the state of the art in column design. Chem Eng Sci 2002 57 1633-1637. 

Veglio F, Slater MJ. Design of liquid-liquid extraction columns for the possible test system Zn/D2EHPA in n-dodecane. Hydrometallurgy 1996 42 177-195. 

It was necessary, because of economic restraints, to locate the americium extraction battery in the same canyon as the mainline PRF TBP extraction equipment. Compromises in americium extraction equipment design and hydraulics were mandated to accommodate the americium extraction system in this existing facility. In particular, all the columns had to be shortened from the optimum heights recommended by the pilot plant studies. The hydraulics of the installed system were such that the organic flowrate to the extraction column (WE-1 Column) was inadequate with the result that the extraction factor was too low to permit quantitative extraction of all the 21tlAm. Furthermore, the combination of a short extraction column and a 1-inch air pulse leg sometimes led to a hydraulic upset whereby the entire column contents were lost recovery from such hydraulic upsets required an hour or more. 

Operating and design specifications of the equipment used in the proposed process Extraction Column, EC... 

The extraction plant was designed for 160 bar maximum pressure and an upper temperature limit of 180°C. All parts which have to withstand pressure are made of 1.4571 stainless steel. The main extraction column comprises 5 segments with 1,5 meters length each. The packed height of the first regeneration column is 3 meters, the second regeneration column contains 1,5 m packing. The inner diameter of all columns is 67 mm. 

A two-column electron capture gas chromatographic system, as described under Apparatus, is used for the analysis. Take 5.0-/ liter aliquots of the concentrated extract and inject them into the gas chromatograph. The injections are made on two different types of specially prepared columns, designated as column A and column B (see section on Experimental Results). 

Clearly, reeults from RP-HPLC of ovarian extracts In two separate studies (16, 17) were consistent both showed the highly polar nature of OH. Also, the extreme retentivenees of this Inhibitor on reverse phase oolume suggested that further purification of OH could be eKhlevsd on columns designed to separate by adsorption rather than by hydrophob1o--abeorpt1on phenomena, I.e., silica gel colume. 

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